Chapter 6Chapter 6

The Solar SystemThe Solar System

Planet ComparisonsPlanet Comparisons

Property Terrestrial Planets Jovian Planets

Distance Close Farfrom the Sun

Size Small Large

Mass Small Large

Composition Rocky Solar-like

Density High Low

Relative Sizes

1 2 3 4 5 6 7 8 9 10 11

JUPITER

Earths

11 Earths can fit across Jupiter’s equator.

Formation of the Solar SystemFormation of the Solar System

The solar system formed from a cloud of The solar system formed from a cloud of gas and dust in a process known as gas and dust in a process known as accretionaccretion..

During the first few million years, matter During the first few million years, matter in the accretion disk of our in the accretion disk of our proto-sunproto-sun coalesced into larger objects called coalesced into larger objects called planetesimalsplanetesimals, with diameters of about , with diameters of about 100 km.100 km.

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We see evidence of We see evidence of accretion disk accretion disk around other stars. around other stars.

For example, For example, Pictoris. Pictoris.

Collisions of Collisions of planetesimalsplanetesimals dominated the dominated the early solar system and these objects early solar system and these objects combined to form our combined to form our planetsplanets..

We see evidence of early collisions in our We see evidence of early collisions in our solar system in the form of solar system in the form of impact cratersimpact craters on on the planets and their moons.the planets and their moons.

In addition to the 9 major planets, there In addition to the 9 major planets, there are at least 65 moons in our solar system. are at least 65 moons in our solar system.

While some of these moons are spherical, While some of these moons are spherical, most look roughly like potatoes.most look roughly like potatoes.

There is still minor debris left over from There is still minor debris left over from the formation of the solar system: asteroids the formation of the solar system: asteroids and comets.and comets.

Bode’s LawBode’s Law a simple rule that gives the distances of the a simple rule that gives the distances of the

planets from the Sun planets from the Sun

AU10

4Planet a of RadiusOrbit

NRN

where N=0, 3, 6, 12, 24…for Mercury, Venus, Earth, Mars, etc.

____ 24 (24+4)/10 = 2.8 AU _______

Planet N Bode’s Law Radii True Orbital Radii

Mercury 0 (0+4)/10 = 0.4 AU 0.39 AU

Venus 3 (3+4)/10 = 0.7 AU 0.72 AU

Earth 6 (6+4)/10 = 1.0 AU 1.00 AU

Mars 12 (12+4)/10 = 1.6 AU 1.52 AU

Jupiter 48 (48+4)/10 = 5.2 AU 5.2 AU

Saturn 96 (96+4)/10 = 10.0 AU 9.5 AU

Uranus 192 (192+4)/10 = 19.6 AU 19.2 AU

Neptune ? ? 30.1 AU

Pluto 384 (384+4)/10 = 38.8 AU 39.5 AU

CeresCeres 2424 2.88 AU2.88 AU

What does Bode’s Law tell us?What does Bode’s Law tell us?

Bode's Law predicted that there should be a Bode's Law predicted that there should be a planet between the orbits of Mars and planet between the orbits of Mars and Jupiter. Jupiter.

The "missing planet" turned out to be the The "missing planet" turned out to be the asteroid belt.asteroid belt.

Arizona Meteor Crater

Approximately 1 mile across

Arizona Meteor crater superimposed over a map of NYC

Odessa, Texas

500 ft wide

Exploration of the Solar System

Mariner MissionsMariner Missions

1973- 1975 Exploration of Mercury and Venus

ProbeProbe MissionMission

Mariner 4 (1965)Mariner 4 (1965) MarsMars

Mariner 10 (1973-1975)Mariner 10 (1973-1975) MercuryMercury

Mariner 6&7 (1969)Mariner 6&7 (1969) MarsMars

Mariner 9 (1971)Mariner 9 (1971) MarsMars

Viking 1&2 (1976- 1982)Viking 1&2 (1976- 1982) MarsMars

Mars Observer (1993)Mars Observer (1993) MarsMars

Mars Global Surveyor ( 1996)Mars Global Surveyor ( 1996) MarsMars

Pathfinder/Sojourner (1998)Pathfinder/Sojourner (1998) MarsMars

Pioneer & Voyager (1970s)Pioneer & Voyager (1970s) Jovian PlanetsJovian Planets

Galileo (1989)Galileo (1989) JupiterJupiter

The Viking Lander – Mojave Desert prior to launch

View of the Martian Surface by Viking I

More recently, the Mars rover “Sojourner” analyzes a Martian rock in 1997.

Voyager Missions –Explore the Outer Planets

Photograph of Jupiter’s Red spot taken by Voyager I

Go To videos – Galileo flybys from JLP

Galileo was another probe that studied Juipiter extensively.

Planets outside of our solar system Planets outside of our solar system have been found recently using have been found recently using Doppler shifts in the spectra of some Doppler shifts in the spectra of some stars.stars.

End of Section.End of Section.

The End.The End.

MatchingMatching

1. Reddish color of Mars1. Reddish color of Mars 2. Red-orange color of Jupiter's belts2. Red-orange color of Jupiter's belts 3. Venus' yellowish clouds3. Venus' yellowish clouds 4. Blue-green color of the surface of 4. Blue-green color of the surface of

Uranus and NeptuneUranus and Neptune 5. The yellow and orange color of Io5. The yellow and orange color of Io

a. ammonia cloudsa. ammonia clouds b. sulfur powderb. sulfur powder c. sulfuric acid clouds c. sulfuric acid clouds d. methane clouds d. methane clouds e. irone. iron

MatchingMatching

6. Has an almost featureless surface6. Has an almost featureless surface 7. The brightest planet seen from Earth7. The brightest planet seen from Earth 8. The most distant planet in 19968. The most distant planet in 1996 9. Last planet in our solar system to be discovered9. Last planet in our solar system to be discovered 10. A possible fossil of single-cell life was found 10. A possible fossil of single-cell life was found

on a meteorite from this planeton a meteorite from this planet

a. Suna. Sun b. Mercuryb. Mercury

c. Venus c. Venus d. Earthd. Earth e. Marse. Mars f. Jupiterf. Jupiter g. Saturng. Saturn h. Uranush. Uranus i. Neptune i. Neptune j. Plutoj. Pluto